go to ebay and amazon and look at tents and lights, fans, and filters, thats your biggest expense.
you have to decide whether you want one or two tents. some people grow one crop from seed all the way to harvest in one tent then start over, some people have a smaller tent for vegging young plants , and a larger tent to flower in. i prefer the two tent method myself, allows you a lot more flexibility.
you're going to need a veg light. i like t5 panels, a couple of 4 tube, 2 foot panels ought to be good for your veg needs.
for flower it depends on what you want to get out of it. i really like the 600 watt hps i got a while ago, its the most efficient of the hid lights and i get MUCH better yields than i was under the 400 i had ( at least 50% more).
i have a 30x30 inch tent for vegging, and a 30X60X80 for flowering. i can fit 3 good sized plants in flower in the 30x60.
all you need in your veg tent should be a couple of clip on fans for circulation. in your flower tent i'd suggest at 6 inch inline fan, something over 300 cfm. and a good filter rated slightly higher than the fan. if you get a 300 cfm fan, get a 320 or higher cfm filter. i like phresh filters, they cost a little more than the cheapos, but they'll last twice as long, and if you aren't afraid of using a drill or a dremel tool, you can take them apart and bake the carbon once a year and use one for 4 or 5 years before you have to replace it.
you need to decide on what medium you're going to use, soil or coco or hydro or w/e, they all have different requirements.
think about that and i'll think of more stuff for you to think about
